 
 
 
25.2.4  Checking required conditions
The assert
command breaks out of a function with an error.
- 
assert takes
bool, a boolean.
- assert(bool) does nothing if
bool is true, it returns from the function with an error if
bool is false.
Example
Define the function:
| sqofpos(x):={ assert(x>0); return x^2; } | 
then:
|  | | “assert failure: x>0 Error: Bad Argument Value” |  |  |  |  |  |  |  |  |  |  | 
 | 
since −4>0 is false.
 
 
